RE: incoming and outgoing

  • From: "Walkowiak, Matt" <Matt.Walkowiak@xxxxxxxxxxxx>
  • To: "[ExchangeList]" <exchangelist@xxxxxxxxxxxxx>
  • Date: Tue, 18 Jun 2002 14:18:09 -0500

Ok, you Internet e-mail newbies - LISTEN UP!!!  Hehe...

To RECEIVE e-mail, this is what needs to happen:
Some guy from Hanover, Indiana wants to send you a message.  He has your
e-mail address (user@xxxxxxxxxx).  After he finishes typing it, he sends
it off to his designated SMTP server, and if he is local or allowed to
relay, the SMTP server takes over from there.  Otherwise, he will get a
"relay not allowed" error message - has nothing to do with you at all...
The SMTP server does a lookup on the part of your e-mail
address.  It asks the world "what IP address should I send stuff
destined for to?"  The world queries the zone record for the
domain and finds the lowest numbered MX record - that's the
IP address the SMTP server is looking for!
Now, the sending SMTP server tries to talk to that IP address it got
from the MX record (gotta make sure that IP address is the same as your
exchange server, or at least it needs to be able to get to your exchange
server) using SMTP (port 25).  This is the first thing you need to
check; have someone from a different ISP try and telnet to your exchange
server on port 25:
telnet 25
Then, make sure the name works, too:
telnet 25
Both should return a 220 response from the Exchange server.
If they do, then the sending SMTP server dumps the data from itself to
your server.  THEN, your Exchange server sees if it is supposed to
answer to  If no, then bad things happen.  If yes, then the
Exchange server sees what account this particular e-mail belongs to
(looks at the part before the @ sign) - if that user exists, it will try
and dump the data into that mailbox.  If it doesn't exist, then your
exchange server will spit back a response to the sender in Hanover,
Indiana informing him that the e-mail account was not found.

If you have gotten this far and you STILL cannot receive e-mails from
the outside in, then you have proven the problem exists on your exchange

If you cannot SEND mail to an outside user in, say, Hanover, Indiana,
there are a few different steps you will want to try.
First, make sure your server can ping it's own IP address, them make
sure it can ping its gateway.  Then see if it can ping a host out on the
Internet - try random numbers till ya find one that responds.  Then, and
here's the hard part, see if you can resolve names - ping
and see if you get an IP address back - don't worry if you don't get a
ping response, we already determined you could ping an IP address - now
we just care if you can resolve an addy.  Then see if you can surf the
Internet.  (The first step I always try is to surf the Internet, then I
work backwards to figure out what is wrong, which is why I wrote all
that before I said to try and surf - a lot of things need to happen to
be able to surf the Internet)

If you can surf the Internet, that means you can talk on ports 80, maybe
443, 53 and if you could ping, port 0.  However, it tells you very
little about being able to send packets out on port 25.  So, from your
Exchange server that can surf the Internet, telnet to some mail server
on port 25 and see if you get a 220 response.  No?  try a few others,
(including your ISP's - that's actually a very good test)  Some ISP's
will block port 25 from leaving their network, so clear that when you
talk to them.
If you did getta 220 response and still cannot send, make sure your
server is not an open relay and listed in one of the spam relay
databases.  Also, make sure that the domain you are sending FROM is
resolvable - many mail server will do a quick check to be sure they are
talking to an actual mail server before they will allow a computer to
send data on port 25.  And make sure the sender (you at your desk using
Outlook) can talk to the Exchange server and that you are either local
or have relay permissions.

Oh, and one more step to do with problems in either direction - TURN ON
SMTP LOGGING!  In Exchange 2000, it's in System Manager, Servers -->
Server name --> Protocols --> SMTP --> Default SMTP.  Go into properties
of that and Enable logging with ALL the extended features.  Logs will
tell you SO much if you are actually recording them :)


Matt Walkowiak

-----Original Message-----
From: Marvin Cummings [mailto:marvc@xxxxxxxxxxxxx] 
Sent: Tuesday, June 18, 2002 12:40 PM
To: [ExchangeList]
Subject: [exchangelist] RE: incoming and outgoing - Re-Vamped!

Can I ask a question on this reply?

Doesn't exchange create a recipient policy on the initial install? I'm
having the same problem where I'm able to send email internally and can
send it outside, I'm just not able to receive any. After being asked to
create a recipient policy I noticed that there was one already created.
this mean I need to create another one? If so should I use a different
address type or the same SMTP?
EX newbie...

-----Original Message-----
From: Andrew J. Shipp [mailto:Andrew@xxxxxxxxxxxxxxxxxx]
Sent: Tuesday, June 18, 2002 1:26 PM
To: [ExchangeList]
Subject: [exchangelist] RE: incoming and outgoing - Re-Vamped!

Have you set yourself up with an external email address / created a
recipient policy?

-----Original Message-----
From: Denise Dorrance [mailto:denisedorrance@xxxxxxxxxxx]
Sent: 18 June 2002 16:29
To: [ExchangeList]
Subject: [exchangelist] incoming and outgoing - Re-Vamped!

Hi All -

I am able to send email to anyone within the domain but cannot send or
receive from or to anyone outside of the company.  Any help would be

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